Based on the heating technician’s report, you conclude that the service pipeline going up to that house must not be “live,” and that one of the numbered valves was probably left in the off position. Without knowing any more details on these two computer systems, what recommendations can you give to the two technicians about to troubleshoot them? Adopting a logical and systematic approach such as the 5 Step Troubleshooting Approach can help you to troubleshoot like an expert! electrical troubleshooting. Switching the power cables back to their original receptacles doesn’t make things better, either. When assisting students with lab projects, what typical problems do you encounter with the circuits they build, and how do these problems typically differ from problems you’ve seen in real-life electronic equipment? Suppose that something goes wrong in this voltage divider circuit, and the load voltage suddenly falls to zero. If you were asked to troubleshoot each system, how would you approach the two systems differently? The unexpected behavior exhibited by the circuit is due to improper locating or soldering of components, component damage due to aging, faults, overheat, and so on. For instance, shorted wiring located far from the equipment enclosure may have caused the components to destruct. Don't have an AAC account? Create one now. A chandelier has five light bulbs in it, and one of them is not working. As usual, there is no schematic diagram supplied with this amplifier that would indicate the proper part numbers. A simple electric circuit is shown in Fig. Understanding basic electricity can be invaluable in both safety, as well as when troubleshooting and repairing an electrical circuit. Each cord has one (male) plug and a receptacle (female) end that accepts up to three plugs: Despite this dangerous wiring, all tools have functioned so far without trouble. Read the following description of an experienced troubleshooter diagnosing an automotive electrical problem, and match the troubleshooter’s steps to those five steps previously described for scientific method: Explain which of the three hypotheses was confirmed by the voltmeter’s reading, and how the mechanic was able to know this. It doesn’t indicate, for example, what the mechanic’s prediction was when deciding to do a voltage check of the battery with the engine stopped and with the engine running. Troubleshooting of an electronic circuit is a process of having a special outlook on components that comes out with remedies to repair it. Read the following description of an experienced troubleshooter diagnosing an mechanical noise problem in a bicycle, and match the troubleshooter’s steps to those five steps previously described for scientific method: Where is the clicking sound coming from on this bicycle, based on the information presented here? 1.Diodes – a two terminal PN junction device that allows the flow of current only in one direction. You remove the chassis cover on the amplifier and look inside. That isn’t a problem, however, because you know how to troubleshoot systems by swapping interchangeable components. Such interconnection is referred to as an electric circuit, and each component of the circuit is known as an element. All the other tools continue to function properly (including all the radios, which is very fortunate because the workers become irritable without their music). The studio engineer will use the individual controls on the mixer to “blend” the inputs for the best recording tone and quality. Efficient troubleshooters never limit themselves to a rigid methodology if other methods are more efficient. This article presents an overview of a simple, but effective, method of investigating an electrical problem. The voltmeter’s test leads are only long enough to check for voltage between pairs of connections at each terminal block. Once students have successfully identified the mechanic’s reasoning, ask them to explain how the prediction of battery voltage uniquely relates to only one of the three hypotheses stated. However, before you step out of the room to go do this, one of your co-workers suggests you start your search at the middle point of the pipeline instead: at the location of valve #4. ‘¥bl« One of the most common troubleshooting techniques taught to technicians is the so-called “divide and conquer” method, whereby the system or signal path is divided into halves with each measurement, until the location of the fault is pinpointed. One day you decide to water your garden, using a garden hose that is already connected to a spigot on the side of your house: When you turn on the valve at the spigot, though, no water comes out the nozzle at the other end of the hose. An electrician is troubleshooting a faulty light circuit, where the power source and light bulb are far removed from one another: AC voltage source TB1 TB2 TB5 TB4 TB6 TB3 Light As you can see in the diagram, there are several terminal blocks (”TB”) through which electrical … Because it is simply more likely that one thing has failed, than that multiple (unrelated) things have failed in just the right way to cause the problem to occur. Fortunately, electrical circuit troubleshooting is an activity that works well for small groups of students to engage in as well as individual students. Where do you think the problem is in this circuit? A mistake common to new students is to consider wild combinations of faults in a broken system before thoroughly considering all the simpler possibilities. What about the electrician’s choice of steps - do you think the voltage measurements taken were performed in the most efficient sequence, or would you recommend a different order to save time? What steps are recommended to take next, if any? You unsolder the transistors from the circuit board and unscrew them from the heat sink, but you cannot read the part numbers on their cases due to the thermal damage. The first computer is a unit that has been in operation for over two years, while the second system is a brand-new prototype, still in the developmental stages. Whether or not the electrician’s sequence was the most efficient depends on two factors not given in the problem: Follow-up question: describe a scenario where the given sequence of voltage readings would be the most efficient. Follow-up question: upon further investigation, you locate the charred remains of an electronic component, located on one of the system’s circuit boards. About the Author: Warren Rhude is president of Simutech Multimedia Inc. an e-learning company that develops computer based training simulations for electrical troubleshooting. I’ll let you determine what the nature of this fault most likely is, and why the strategy employed in this scenario probably wasn’t the wisest. Despite the undeniable power of the “swap interchangeable components” strategy, it is not fool-proof. Unfortunately, in your rush to get to the job site you forgot to bring your test equipment. When you flip it’s power switch on, welder #2 turns on just like it should. The course presents€an overview of other common electrical work activities such as preventive maintenance. basic electrical theory & troubleshooting. It’s wise to be prepared with a troubleshooting plan. Describe a procedure for determining the location of the problem (chandelier vs. bulb), without using any electrical test instruments. While this simple reasoning may apply in finding “open” faults in long lengths of wire, it does not necessarily hold true for more complex circuits, as other faults may result in similar effects. This troubleshooting strategy is sometimes referred to as the “divide-and-conquer” method, because it divides the system into small sections to optimize troubleshooting time and effort. ‘¥b,©Bdc‰Õ8²±DjÙXB5Žl,Y5Žl,&-Ž“ÅV‹ãdc1jqœl,5Žl,z5Žl,:5Žl,²G6I#‹¨Æ‘E«Æ‘-ªÙ×rI ˆ—u-¶êúm ZÙU¯FÙq«FÙu5 DÙñϪF¹Ó´. With the load connected, the parallel combination of load and 1 kΩ resistor results in an effective resistance of less than 1 kΩ on the lower half of the divider, resulting in a voltage of less than half the total supply voltage.). A very powerful method for discerning cause-and-effect relationships is scientific method. Explain why or why not. Field testing and repairing can be accomplished with basic tools and repair parts which should include the following-: A quality multimeter [multitester] capable of reading less than one ohm and with a specific diode testing fun<:tion. I’ve left these steps for you to elaborate. If the swapped component is indeed faulty, but in such a way that it causes a different part of the system to fail with connected to it, this technique will cause a failure in the system where the faulty component is moved to. Although the symptoms in each system are very similar, the histories of the two systems are not. Read Online Hvac Basic Electrical Troubleshooting Guide Hvac Basic Electrical Troubleshooting Guide Thank you unquestionably much for downloading hvac basic electrical troubleshooting guide.Maybe you have knowledge that, people have see numerous period for their favorite books taking into account this hvac basic electrical troubleshooting guide, but end stirring in harmful downloads. Once students have successfully identified the mechanic’s reasoning, ask them to explain how the prediction of noise rhythm distinguishes which part of the bicycle is making the noise. Electrical Troubleshooting October 2006 PASSAGEMAKER 103 of locations throughout his electrical system. If test passes, hypothesis is provisionally confirmed. But which one could it be? One commonly accepted algorithm (series of steps) for scientific method is the following: This methodology is also very useful in technical troubleshooting, since troubleshooting is fundamentally a determination of cause for an observed effect. Why should we first consider single faults to account for the problems the circuit is having rather than considering interesting combinations of faults which would account for the same problems? TYPE (BASIC) 54:39 – ACC Diagnostics . A “virtual” troubleshooting exercise such as this one is a good way to start students thinking in the right ways to becoming effective troubleshooters. Basic Electrical Engineering Pdf Free Download | BEE Notes Pdf. ... 49:30 – Advanced Troubleshooting Techniques for Two-Wire Systems Overview . Ohm’s Law is the basic formula used in all AC and DC electrical circuits. This methodology is also very useful in technical troubleshooting, since troubleshooting is fundamentally a determination of cause for an observed effect. As an illustration of this principle, you might want to elaborate on your own experiences as an electronics instructor. Some students may question this logic, believing that the left and right channels of a stereo amplifier would be mirror-symmetric rather than identical, and thus possibly contain different components. Your co-worker’s strategy is based on the principle of dividing the gas pipeline into halves, and checking for pressure at the half-way point. Remember that the speaker cables detach easily from the speakers and from the amplifier. ÜzP³¶ÆFM ¸-¹¸§HÊöˆËî*ã§Ö˜3TMµr†eãU™Ä—´,håVƒÛNÙ:$jiä Æa9Ä«qœâÔ8^ÉêÕÉ ‡]UC(û겯^7YXgÕ8²±œ´8$Ë­‡dc9jqH6–ƒG6–½G6–G6–Y#ˤƑeTãÈƲUãÈÆRÒâ°l,µZ–¥¨ÅaÙXÊÆz§ A very good way to determine which of these components is faulted is to swap cables and speakers between sides, but I’ll let you determine which component swaps test which components. electricity can kill you! A technician following the “divide-and-conquer” troubleshooting strategy begins by measuring voltage across the lower resistor (finding 0 volts), then measuring voltage across both resistors (finding 12 volts): Based on these measurements, the technician concludes that the upper resistor must be failed open. From this information alone, determine what sections of this “network” are good, and what sections are suspect. This circuit is called a voltage divider, because it presents a fractional portion of the total voltage to the load: (Of course, with no load connected, the voltage across the lower resistor would be precisely 6 volts. He then swapped speakers and speaker wires, and consistently found that whatever speaker was plugged into the left channel did not make sound, but the speaker plugged into the right channel always did. The terminal blocks are located too far apart to allow for voltage checks between blocks (say, between one connection in TB2 and another connection in TB3). Nearly anyone who is familiar with basic electronic theory can learn troubleshooting techniques and fix many types of electronic failures. Describes and illustrates techniques for troubleshooting electrical and electronic circuits with a focus on control circuits and motors. What do you do? Troubleshooting Regulations BASIC ELECTRICAL AND ELECTRONIC COMPONENTS •ACTIVE DEVICES – devices or components which requires external source to their operation. Details basic electrical theory and troubleshooting. This is a common mistake students make when applying the “divide-and-conquer” method of troubleshooting: that whatever component(s) located between the point of good measurement and the point of bad measurement must be the source of the problem. Then suddenly both the worklight and the circular saw in the lower-right corner of the illustration stop working. Notes: This simple troubleshooting technique is applicable to a wide variety of electrical, electronic, and other types of systems: swap the suspect component with an identical component known to be functional, and see observe whether or not the problem changes location.. of the generator, troubleshooting is relatively easy. This system has a problem, though. In the next diagram, you can see the electrician’s voltage checks, in the sequence that they were taken: Based on the voltage indications shown, can you determine the location of the circuit fault? Deciding to apply your ßwap interchangeable components” troubleshooting strategy, you turn off both welders’ power switches, then turn off the disconnect switches at both receptacles and swap the power cables between receptacles: When you turn the disconnect switches on and try to start both welders, you find that neither one turns on now! As Murphy’s Law would predict, electrical control system issues usually happen with the worst possible timing. Scenario #2, outcome #1: problem is not in the microphone. A music recording studio is equipped with three microphones, each of which connect to the “mixer” panel by means of shielded cables: The purpose of the mixer is to function as a multi-channel audio signal amplifier, to control the volume of each sound channel so that a good “mix” is obtained for recording. At a construction site, several electric “arc” welders are plugged into 480 volt receptacles. A new residential neighborhood is being built, and you are working as a member of the construction crew. interconnection of electrical devices. Published under the terms and conditions of the Creative Commons Attribution License. Each receptacle has its own safety disconnect switch and fuse overcurrent protection: You, as an electronics technician working at the job site, happen to be walking past these welders when one of the welding personnel stops you to ask for help. The gas pipeline servicing these houses is laid out in the following manner: Each black dot on the diagram is a shutoff valve, used for isolating different sections of the service pipeline. The fault is located somewhere between TB3 and TB4. Components known to be okay include the left speaker, left speaker cable, and power cord for the amplifier. Discuss with your students the relationship between the mechanic’s steps and the steps given for scientific method. Follow-up question: describe the general principle you used to locate the suspect area of this power network. A similar hazard occurs if the swapped component was damaged because of other components in the system that it’s connected to. I do not expect that you will provide specific, technical answers, because I have given very little information about the malfunctioning systems. Experienced technicians have developed a method for troubleshooting. Failure of this pump will result in the loss of a generator currently producing half of the station’s power output. Identify the most likely location of the fault in this system, and explain why the ßwap interchangeable components” strategy got you into trouble. Basic Electronic Troubleshooting Techniques. Upon opening the cabinet door for this equipment, your nose is greeted by the pungent odor of burnt circuit board (a smell you are unlikely to forget, once having experienced it). As an industrial electrician, you'll encounter many complex electrical circuits and drives that will break down as they age. Scenario #1, outcome #1: problem is not in the microphone. Explain why your co-worker’s idea is better, and also what your next step would be if: (a) you did find pressure at that point, and (b) if you did not find pressure at that point. How do you (and the mechanic) know? Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. Electrical problems can sometimes be intimidating and somewhat daunting at first. This is a common assumption made by beginning troubleshooters: that the most obvious failure is the only failure, or that it must be the primary failure. Each one is identical to the other at the circuit level, because each channel is expected to perform exactly the same. Basic Electrical Troubleshooting A boiler feed pump being powered by two 3500 HP inducti on motors appears to be developing a problem. You know that the main utility connection at the street is “live,” because the gas heater in the contractor mobile building is working just fine. What I want is for you to think in general terms: how might the scope of possible problems differ between any two similar systems, one of which is proven while the other is untried? Basic Electrical Troubleshooting for Everyone (Gnv64) - Free ebook download as PDF File (.pdf), Text File (.txt) or read book online for free. This seems especially true when students answer troubleshooting questions on written exams. 1.1. This problem gives students a chance to explore the “divide and conquer” strategy of troubleshooting in a context that is very simple and does not require knowledge of electricity. We will add more posts soon on many topics such as how to build a solar generator, and this post will help build the basics on which those posts will expand. Electricity has long been recognized as a serious workplace hazard, exposing employees to electric shock, electrocution, burns, fires and explosions. Tools and techniques. Rest assured, with the help of your vehicle’s repair manual and some basic electrical troubleshooting knowledge, everybody should be able to find and fix most electrical problems in no time. Upon disassembling the divider circuit and checking resistance with an ohmmeter, though, both resistors are revealed to be in perfect operating condition. Can you check it out?”. Your friend has already done some troubleshooting of his own: after turning off the amplifier and letting the smoke clear, he turned it back on at low volume to find that the left channel is dead, but the right channel is still working. Read the part numbers off the power transistors for the right channel output! •voltage always follows the path of least resistance •it takes less than 1 amp of current to stop your heart. Be sure to discuss this possibility with your students, and the reasoning why the one extension cord would be more likely to be faulted than two separate devices. What ranges of problems might you expect from each system? Ensure you take the proper precautions. An electric circuitis an interconnection of electrical elements. Since garden hoses easily detach from spigots and nozzles alike, they lend themselves well to the so-called “divide-and-conquer” method of troubleshooting. When actually working on real circuits, students seem more likely to first look for simple causes. The problem could be in the chandelier’s wiring (open wire connection, open connection in socket), or in the bulb itself (burned-out filament). The following four troubleshooting techniques are popular and widely used to find defects in communication equipment. Troubleshooting Plan | Electronics Troubleshooting Techniques. You may answer this objection by appealing to the indistinguishable sound of the two channels, when listened to separately (mono). This is not good, because the person who called you for help is beginning to cast angry looks in your direction, and you are fairly sure the operator of welder #2 won’t be much happier when he returns to find his welder non-functional as well. By the way, this type of question is excellent for a written test! Basic Electrical Troubleshooting; Advanced Electrical Troubleshooting; PDF Library. The electrician is using a voltmeter to check for the presence of voltage between pairs of terminals in the circuit. A friend of yours brings you their damaged stereo amplifier, hoping that perhaps you would be able to repair it cheaper than the local electronics repair shop. Explain how you might go about troubleshooting this problem, using no test equipment whatsoever. Operators are complaining that a large compressor on several occasions has failed to start. Race cars, kit cars, street rods, restorations and trailers. Describe another scenario where a different sequence of voltage readings could have saved time in locating the problem. Challenge question: can you think of a scenario where this troubleshooting procedure could cause additional failures in a system? Discrete Semiconductor Devices and Circuits, CEVA Debuts Integrated Hardware and Software Platform for Contextually-aware IoT Devices, The Zambroombi: Roomba’s Next Ultrasonic Competitor, Simplifying Hardware Security Implementation for IoT Nodes, Semiconductor Basics: Materials and Devices, Formulate an hypothesis (an educated guess), Predict a unique consequence of that hypothesis. To troubleshoot, you simply follow logical, step-by-step procedures to arrive at a solution. Scenario #2, outcome #2: microphone #2 is faulty. safetyis the most important thing. Basic electrical tools including cutters, soldering iron, You decide to go to valve #8 and check for gas pressure at that point in the pipeline with a portable pressure gauge, then checking the pressure at each valve location down the pipeline until you find where there is good gas pressure. In Ockham’s own words, the principle is as follows: Applied to troubleshooting electric circuits, one could re-phrase Ockham’s Razor as such: Justify the use of Ockham’s Razor in troubleshooting circuits. If test fails, go back to step #2. Swap the non-working bulb for one of the other four working bulbs, and see if the problem moves with the bulb. Utilizing safe, effective troubleshooting techniques also ensures compliance with OSHA 1910.333(a)(1) which covers the requirements for de-energized work. When components have been heated to such a degree that they emit strong odors, the damage is often visible as well, which makes it easier to locate problem areas. Determination of cause for an observed effect is this the only possible that! Proper part numbers only component visibly damaged and you are working just fine,.!, types of dc Motors several electric “ arc ” welders are plugged into 480 volt receptacles to,! As a member of the power cables back to Step # 2 are still “ dead ”... 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